System to generate signals for control or regulation of a controllable or regulable chassis

ABSTRACT

Basing on signals (Vi) representing the vertical movements of the vehicle body at selected points (Pi) of the body, and basing on second signals (Xarvl&#39;, Xarvr&#39;, Xarhl&#39;, Xarhr&#39;) representing the relative movements between the wheel units and the body of the vehicle, the inventional system infers selected components of movement of the vehicle body, such as heave, roll and pitch movements or the vertical movement of the body at the front and rear axles as well as the roll movement. These components of movement are weighted differently. Basing on these differently weighted components of movement, second body movements are inferred at the points where the wheel suspension systems attach to the body. By comparison of the second body movements (Vagvl, Vagvr, Vaghl, Vaghr) to the pertaining relative movements between the wheel units and the body there are actuation signals formed for the respective suspension system, in a way such that the selected components of movement can be influenced separately from one another in the sense of a reduction.

PRIOR ART

The invention is based on a system according to the category of the mainclaim.

To improve the travel comfort of passenger cars or trucks, the design ofthe chassis is of considerable significance. Necessary for it aresufficient spring and/or damping systems as components of a chassis.

With passive chassis, which presently continue to be used predominantly,the spring and/or damping systems are designed at the time ofinstallation to be either relatively hard ("sporty") or relatively soft("comfortable"), depending on the predicted use of the vehicle.Influencing the chassis characteristic during the travel operation isnot possible with these systems.

With active chassis, in contrast, the characteristic of the springand/or damping systems can be influenced during the travel operation inthe sense of a control or regulation, depending on the state of travel.

What must first be considered for the control or regulation of such anactive chassis are the needs of the passengers and cargo as well as thetype of road surface. Viewed as impairments of travel comfort by thepassengers or by a cargo sensitive to shocks are the vertical movementsof the vehicle body. the causes of these vehicle body movements arestimulations by road surface unevennesses and variations of the state oftravel, such as steering, braking and acceleration.

A minimization of the vehicle body movements results in a high travelcomfort. To counteract the vehicle body movements by an active springand/or damping system in a diminishing way, the U.S. Pat. No. 3,807,678describes a system for chassis control where the vehicle body isisolated from stimulations by the road surface unevennesses. To thatend, suspension systems are arranged between the body and wheels of achassis in such a way that a force can be applied between the body andthe wheels. This force is determined by comparisons of sensed relativemovements between vehicle body and wheels to sensed body movements. Sucha system for minimization of body movements is generally called a"skyhook control."

A disadvantage of this system is constituted in that the minimization ofthe body movements is performed separately for each system comprised ofa wheel unit and the prorated vehicle body and of the suspensionarranged between wheel unit and vehicle body. This "local" version ofthe skyhook control thus makes no allowance for the collective bodymovements, such as heave, roll and pitch movements or the verticalmovement of the body at the front and rear axles. Such collective bodymovements, e.g., are the consequence of steering, braking andaccelerating maneuvers.

The problem underlying the present inventional system is to influenceselected components of movement independently from one another and atdifferent weighting, in the framework of influencing the body movements.

ADVANTAGES OF THE INVENTION

As compared to the prior art, the present invention offers the advantagethat selected components of movement, such as heave, roll and pitchmovements or the vertical movement at the front and rear axles, can beinfluenced along with the roll movement, separately from one another andto different extents.

According to the invention, signals are determined which represent thevertical movement of the body at selected points. Basing on thesesignals, specific components of movement are inferred, making itpossible to weight these components differently. These weightings may beeffected, e.g., under allowance for the state of travel of the vehicle,such as braking, acceleration and steering.

Basing on these differently weighted motive components, weightedvertical movements of the body are inventionally inferred at pointswhere the wheel suspension systems attach to the body.

Moreover, signals are determined which represent the relative movementsbetween the wheel units and the body of the vehicle (spring deflectionmovements).

By comparing the weighted vertical movements at the points where thewheel suspension systems attach to the body to the pertaining relativemovements between the wheel units and the vehicle body, actuationsignals for the respective suspension system are formed in such a waythat the selected components of movement can be influenced separatelyfrom one another in the sense of a reduction.

To influence the movements of the vehicle body, suspension systems arearranged between a wheel unit each and the body, which suspensionsystems can influence the movements between the wheel units and thevehicle body. The suspension systems may consist, e.g., of spring and/ordamping systems. For control or regulation of the chassis, the springand/or damping systems are configured to be adjustable in such a waythat the spring or damping properties of the adjustable spring and/ordamping systems are adjustable at least in two stages, that is, that thespring and/or damping systems to be controlled/regulated feature atleast two spring and/or damping characteristics.

BRIEF DESCRIPTION OF THE DRAWINGS

An embodiment of the invention is illustrated in the drawings and willbe more fully explained in the following description.

FIG. 1 shows a spatial vehicle model, while FIG. 2, 3 and 4 illustratethe essential elements of the inventional system in the framework ofthis embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The preferred embodiment depicts the inventional system for control orregulation of a chassis with the aid of a block diagram. The vehiclecomprises in this embodiment four wheel units and two axles, thechassis, and adjustable dampers whose characteristic is adjustable in atleast two stages.

FIG. 1 shows a simple spatial model of a longitudinally symmetric,four-wheel and two-axle vehicle. In the following, index i designatesthe pertaining axle; that is, index i=h indicates the propertiespertaining to the rear axle while i=v stands for the propertiespertaining to the front axle. Reference 30 represents spring and dampingsystems comprised each of a spring with the spring constant Ci and adamper of parallel arrangement with the damping constant di. The wheelsare referenced 31 and described in model fashion each by thesuccessively arranged bodies with the masses Mri and the springrepresenting the stiffness of the tire with the spring constant Cri. Theroad surface is marked 33, while the body with the mass Mk is referenced32. The center of gravity S of the vehicle body is located a distance afrom the front axle and a distance c from the rear axle, while bsignifies one-half the track.

FIG. 2 shows in the framework of this embodiment the essential elementsof the system. Referenced 11 are first means for determining the vehiclebody movements, while reference 12 denotes within a dashed border secondmeans for determination of the selected components of movement withlinkage units 121, 122 and 123. Reference 13, within dashed bordering,represents third means for the weighting, with 131, 132 and 133referencing multiplicative and/or additive linkages. References 14 and15 represent fourth means for linkage and fifth means for data valuationand changeover of the damping characteristic, with reference 14 showingin dashed bordering a combination of linkage units 141, 142, 143 and144, while reference 15 shows in dashed bordering a combination of logicunits 151. Marked 16 and 17 are sixth means for determination of thetransverse and longitudinal movements of the vehicle. References (18ij)are eighth means for determination of the spring deflection movements.

FIG. 3 shows the mode of operation of the logic units 151, with 1511indicating a data retrieval, 1512 and 1513 value comparisons, and 1514and 1515 means for changeover of the damping characteristic. Fed to thedata retrieval 1511 are set values and/or the signals--sensed in theeighth means (18ij)--representing the spring deflection movements,and/or signals of the means 16 and 17 and/or variables representing orinfluencing the state of travel, such as the travel speed and/or ambienttemperature.

In FIG. 4, reference 41 indicates ninth means for error recognition, towhich the signals of the first means (11) for determination of thevehicle body movements are relayed. Referenced 42 and 43 are tenth meansfor data valuation and eleventh means for error display.

The following will illustrate, with the aid of FIGS. 1, 2, 3 and 4, themode of operation of the system for generating signals for control orregulation of an active chassis as described in this embodiment.

Determined in the first means (11) are first signals (Vi) representingindirectly or directly the velocities of the vehicle body in verticaldirection at selected points (Pi) of the body. The first signals (Vi),e.g., may be obtained by integration of acceleration sensor signals, theacceleration sensors being so fastened on the vehicle body at points(Pi) that they will capture the vertical accelerations of the vehiclebody. The conditions for selection of the points (Pi) will be addressedyet in greater detail in the course of this description.

The first signals (Vi) now are passed to the second means (12) wherethey are linked to one another. This linkage occurs in the units 121,122 and 123.

This linkage unit, the same as all others of the system, can be realizedin electronic digital or electronic analog fashion using electroniccomponents, by simulation of a matrix representing the linkageproperties.

The linear linkages of the first signals (Vi) among one another in thesecond means (12) can be represented mathematically in matrix notation,requiring a differentiation between two cases:

First Case:

Represented by the first signals (V1, V2, V3) are the verticalvelocities of the vehicle body in vertical direction at three selectedpoints (P1, P2, P3) of the body. In this case, the linkage in the secondmeans (12) is obtained by the following matrix ##EQU1## where detA=(y2-y3)*x1+(y3-y1)*x2+(y1-y2)*x3 and

xi and yi are the coordinates of the point (Pi) with regard to abody-fixed coordinate system with the center of gravity of the body aszero point, where the index i=1,2,3 and the vehicle body is in modelfashion assumed to be two-dimensional, and

the coordinates (xi, yi) of the points (Pi) are so selected that (det A)is not zero.

In the second means (12) the first signals (V1, V2, V3) are thuscombined linearly as described hereafter. ##EQU2##

The linkages among one another are obtained in mathematically formalfashion by matrix multiplication of the three-component vector (V1, V2,V3) by the matrix (1). The individual units 121, 122 and 123 may be laidout as multiplying or adding units, for instance according to the vectormatrix multiplication algorithm, as follows.

Unit 121:

1/(det A) * [V1*(x2*y3-x3*y2)+V2*(x3*y1-x1*y3)+V3*(x1*y2-x2*y1)]

Unit 122:

1/(det A) * [-V1*(x2-x3)-V2*(x3-x1)-V3*(x1-x2)]

Unit 123:

1/(det A) * [-V1*(y2-y3)-V2*(y3-y1)-V3*(y1-y2)]

Second Case:

The first signals V1, V2, V3, V4 represent the vertical velocities ofthe vehicle body in vertical direction at four selected points (P1, P2,P3, P4) of the body. In this case, the linkage in the second means (12)is given by the following matrix ##EQU3## where B11=B12=-x3/(x1-x3) and

B13=B14=x1/(x1-x3) and

B21=-B22=y1/(y1² +y3²) and

B23=-B24=y3/(y1² +y3²) and

B31=B32=-1/(x1-x3) and

B33=B34=1/(x1-x3) and

xi and yi are the coordinates of the point (Pi) with regard to abody-fixed coordinate system with the center of gravity of the body aszero point, where the index i=1,2,3,4 and the vehicle body is in modelfashion assumed to be two-dimensional, and

the coordinates (xi, yi) of the points (Pi) are so selected that x3 isnot equal to x1, y1² +y3² >0, x2=x1, y2=-y1, x4=x3 and y4=-y3.

In the second means (12) the signals (V1, V2, V3, V4) are thus linearlycombined as described hereafter. ##EQU4##

The linkages among one another are obtained in mathematically formalfashion by matrix multiplication of the four-component vector (V1, V2,V3, V4) by the matrix (2). The individual units 121, 122 and 123 can inthis case be configured as multiplying and adding units, for instanceaccording to the vector matrix multiplication algorithm, as follows.

Unit 121: 1/2 * (V1*B11+V2*B12+V3*B13+V4*B14)

Unit 122: 1/2 * (V1*B21+V2*B22+V3*B23+V4*B24)

Unit 123: 1/2 * (V1*B31+V2*B32+V3*B33+V4*B34),

where the variables Bij are defined as described above.

The linkage results (z', alpha' and beta') prevailing in both cases onthe outputs of the second means (12), respectively on the outputs of thefilter units (121, 122, 123), represent the heave, roll and pitchvelocities. The pivots of the vehicle body about its longitudinal ortransverse axis are signified here by alpha or beta, respectively, andthe vertical displacement of the center of gravity of the body by z.Alpha', beta' and z' are the respective first time derivations of thevariables alpha, beta and z.

The third signals (z', alpha', beta') representing the heave, roll andpitch velocities of the vehicle body are weighted in the third means(13) by the linkages 131, 132 and 133. This takes place bymultiplications of the third signals (z', alpha' beta') by the variablesgh, gw and gn and may be effected separately from one another.

The weighting of the third signals (z', alpha', beta') in the thirdmeans (13) is favorably carried out depending on the travel dynamics,such as longitudinal and/or transverse movements of the vehicle, and/orthe ambient temperature. To be understood as travel dynamics are herespecifically the transverse and/or longitudinal acceleration of thevehicle and/or the travel speed. The travel dynamics may be captured,for instance in the sixth means (16, 17) as described hereafter:

The transverse movements of the vehicle can be determined from signalsof a steering angle sensor, with these signals being utilized also for aservo steering control or regulation.

longitudinal movements of the vehicle can be determined from signals ofwheel speed sensors which, e.g., are used also for an antilock system.

The longitudinal and/or transverse movements of the vehicle can bedetermined from signals of appropriately positioned accelerationsensors.

The longitudinal movements of the vehicle can be determined by theposition of the gas pedal and/or brake pedal actuated by the driver.

In summary, it can be said regarding the influencings in the third means(13) that here a definitive influencing of the heave, roll and pitchmovements is possible, for instance to emphasize or dampen a specificmovement especially in the subsequent data evaluation and changeover ofthe damping characteristic. Thus, the weighting will favorably beselected depending on steering, braking and acceleration maneuvers ofthe vehicle, in order to cause the roll and pitch movements of thevehicle body initiated thereby to ebb off swiftly.

In a simple configuration of the inventional system, the third means(13) may be circumvented. However, a specific influencing of the variousmotive components is then not possible.

In the case of a four-wheel, two-axle vehicle where spring and/ordamping systems are arranged between each wheel and the vehicle body,the weighted linkage results (gb * z', gw * alpha, gn * beta) prevailingon the output of the third means (13) or the uninfluenced linkageresults (z', alpha', beta') which under circumvention of the third means(13) prevail on the outputs of the seconds means (12) are linked amongone another in the fourth means (14), which latter can be characterizedin matrix notation as follows: ##EQU5## where a1 is the distance betweenthe center of gravity of the vehicle body and the damper attachmentpoints above the front axle,

a2 is the distance between the center of gravity of the vehicle body andthe damper attachment points above the rear axle,

2*b1 is the distance of the damper attachment points on the vehicle bodyabove the front axle, and

2*b2 is the distance of the damper attachment points on the body abovethe rear axle.

Hence, the weighted linkage results (gh * z', gw * alpha', gn * beta')or the unweighted third signals (z', alpha', beta') are linearlycombined in the fourth means (14) as described hereafter. Carried outexplicitly here is only the case where the weighted linkage results(gh * z', gw * alpha', gn * beta') are processed in the fourth means(14). The unweighted third signals (z', alpha', beta') are processedanalogously. ##EQU6##

The linkages among one another are obtained in mathematically formalfashion by matrix multiplication of the three-component vector (gh * z',gw * alpha', gn * beta') by the matrix (3). The individual units 141,142, 143 and 144 may in this case be configured, for instance accordingto the vector matrix multiplication algorithm, as multiplying and addingunits as follows.

Unit 141: gh * z'+(gw * alpha'*b1)-(gn * beta' * a1)

Unit 142: gh * z'-(gw * alpha'*b1)-(gn * beta' * a1)

Unit 143: gh * z'+(gw * alpha'*b2)+(gn * beta' * a2)

Unit 144: gh * z'-(gw * alpha'*b2)+(gn * beta' * a2),

where the variables a1, a2, b1, b2 are defined as described above.

Prevailing as results of the linkages on the outputs of the fourth means(14) are the linkage results (Vagvl, Vagvr, Vaghl, Vaghr) representingthe weighted vehicle body velocity in vertical direction at the pointswhere the wheel suspension systems attach to the body.

The linkage results (Vagvl, Vagvr, Vaghl, Vaghr) thus obtained arepassed on to the fifth means (15). Here, the mathematical signs andamounts of the linkage results (Vagvl, Vagvr, Vaghl, Vaghr) are analyzedand adjustments made of the respective adjustable damping system,depending on the mathematical sign and magnitude of the amount.

This is done separately for each wheel suspension system in the logicunits 151, the mode of operation of which is illustrated in FIG. 3.Entered by the data retrieval 1511 are set values Sij and/or the signals(Xarij) of the eighth means (18ij) and/or signals of the sixth means(16, 17) and/or variables representing or influencing the state oftravel, such as the vehicle speed and/or ambient temperature. Index ialways stands for the front or rear position on the vehicle, index jalways for the right or left position on the vehicle.

Determined in the eighth means (18ij) are the relative movements betweenthe wheel units and the vehicle body. To that end, second signals(Xarhl', Xarhr', Xarvl', Xarvr') representing the spring deflectionvelocities between the wheel units and the body are captured indirectlyor directly. This may be accomplished by capturing the spring deflectionvelocities using appropriate sensors and/or by capturing the springdeflection paths and subsequent differentiation.

The linkage results (Vagvl, Vagvr, Vaghl, Vaghr) are compared each to aset value Sij in the value comparison (1512). This set value may assumea constant value for the respective damping system and/or depend onvariables representing or influencing the state of travel, such astransverse movements, longitudinal movements, travel speed and/orambient temperature.

If the amount |Vagij| of the linkage results is smaller than thepertaining set value Sij, the signal N prevails on the output of thevalue comparison (1512). In this case, no changeover of the dampingcharacteristic is performed.

If the amount |Vagij| of the linkage results is greater than thepertaining set value Sij, the signal Y prevails on the output of thevalue comparison (1512). In this case, the mathematical sign of theproduct Vagij * Xarij' is analyzed in the unit (1513).

If this product Vagij * Xarij' is greater than zero, the signal Yprevails on the output of unit (1513), if it is less than zero, thesignal N.

The signal Y on the output of unit (1513) is transmitted to the firstmeans (1515) for changeover of the damping characteristic, where achangeover to a harder damping characteristic of the respective dampingsystem is carried out.

The signal N on the output of unit (1513) is transmitted to the secondmeans (1514) for changeover of the damping characteristic, where achangeover to a softer damping characteristic of the respective dampingsystem is performed.

An advancement of the arrangement of units (1512) for data valuation andchangeover of the damping characteristic as described above as anembodiment may be constituted by comparing the amounts of the linkageresults (Vagij) to several pertaining set values S1ij, S2ij, S3ij . . .This may favorably be performed in several value comparisons (1512/1,1512/2, 1512/3 . . . . Depending on the more detailed amount value of|Vagij| thus obtained, specific damping characteristics of therespective damping system can be adjusted, whereas with the arrangement(FIG. 3) described as embodiment only the next harder or next softerstage will be activated.

An especially simple embodiment of the inventional system is thetwo-stage configuration of the damping systems with a hard and a softchassis characteristic. In this case, the stages "hard" or "soft" areadjusted in the means for changeover of the damping characteristic 1514or 1515.

In the embodiment described so far, the heave, roll and pitch movementshave been selected as motive components which can be weightedindependently from one another and to different extents. However, thisis not mandatory; basically, selective components of movement of thevehicle body may be based upon. Important for the arrangements is thecase in which the vertical movement of the body on the front and rearaxles as well as the roll movement are selected as components. However,this necessitates a computation and weighting procedure which deviatesslightly from that illustrated in FIG. 2. Therefore, this modifiedprocedure is briefly illustrated.

1. Determination of heave, roll and pitch velocities from measuredvertical body movements at individual--three or four--points (as in theembodiment described already).

2. Computation of the vertical velocities of the body (z_(v) ', z_(h) ')at the front and rear axles from the determined heave and pitchvelocities according to

    z.sub.v '=z-a * beta'

    z.sub.h '=z-c * beta'

3. Weighting the velocities z_(v) ', z_(h) ' and the pitch velocityalpha (independently from one another):

    z.sub.vg '=gvo * z.sub.v '

    z.sub.hg '=ghi * z.sub.h '

    alpha.sub.g '=gw * alpha'

The weighting factors gvo, ghi and gw may favorably be selecteddepending on variables representing and/or influencing the state oftravel, such as the travel speed, braking, steering and/or accelerationmaneuvers of the vehicle and/or ambient temperature.

4. Computation of the weighted heave and pitch velocities z_(g) ' andbeta_(g) ' from the weighted velocities z_(vg) ' and z_(hg) ':

    z.sub.g '=[c/(a+c)] * z.sub.vg '+[a/(a+c)] * z.sub.hg '

    beta.sub.g '=-[1/(a+c)] * z.sub.vg '+[1/(a+c)] * z.sub.hg '

It should be noted that the steps 2 through 4 may also be combined asdescribed in the following: ##EQU7## where g11=[c/(a+c)] *gvo+[a/(a+c)] * ghi

g13=-[(a*c)/(a+c)] * [gvo-ghi]

g22=gw

g31=-[1/(a+c)] * [gvo-ghi]

g33=[a/(a+c)] * gvo+[c/(a+c)] * ghi

5. Computation of the weighted body velocities (Vagvl, Vagvr, Vaghl,Vaghr) in vertical direction at the attachment points of the dampers tothe body from the weighted heave, roll and pitch velocities accordingto: ##EQU8## (as already in the described embodiment).

If in the first means (11) the first signals (Vk, with k=1 through 4)representing the velocities of the vehicle body in vertical direction atfour selected points (P1, P2, P3, P4) of the body are determined,another favorable embodiment of the inventional system is arrived at, asdescribed hereafter.

By capturing the vertical body velocities at four points, agreementexists regarding the determination of the three motive components heave,pitch and roll movement. This may be utilized for error recognition ofthe sensor system and/or for signal processing of the inventionalsystem.

To that end, as illustrated in FIG. 4, the first signals (Vk, with k=1through 4) are fed to the ninth means (41). These ninth means (41) linkthe first signals (Vk, with k=1 through 4) to the coordinates of thepoints (Pi) where the body movements are determined. This linkagesatisfies the following mathematical rule: ##EQU9## where the elementsrik are given by the matrix R ##EQU10## and yi represent the coordinatesof the point (Pi) in the transverse direction of the vehicle with regardto a body-fixed coordinate system having the center of gravity of thebody as zero point, where the index i=1,2,3,4, y2=-y1 and y4=-y3 and thevehicle body is in model fashion assumed to be two-dimensional.

The output signal (r) of the ninth means (41) is now compared in thecomparator unit (42) to the specified thresholds (tuning parameters). Ifthe value (r) exceeds this threshold, an error signal (F) is displayed.

We claim:
 1. A semi-active control system for controlling and regulatinga vehicle, said vehicle including a vehicle body which is subject toheave, pitch, and roll movements, said body connected to a plurality ofwheels disposed on at least two axles, a plurality of adjustablesuspension systems, said plurality of suspension systems connected atrespective attachment points to said body and to respective said wheels,said plurality of suspension systems adjustable to influence movementsof respective wheels relative to said body, said control systemcomprising:means for determining a plurality of first signals whichrespectively represent velocities of first body movements at respectivepreselected points of said body; means for generating second signalswhich respectively represent movements of respective wheels relative tosaid body; control means for controlling said suspension systems, saidcontrol means including: means for determining first components ofmovement of said vehicle body based on said first signals and generatingthird signals representing said first components, said first componentsof movement including only vertical movements of said body at the axlesand roll movements of said body; means for determining second bodymovement signals of said body based on said first components, saidsecond body movement signals representing movement velocities of saidvehicle body at said plurality of attachment points; and means forgenerating actuation signals for actuating said plurality of suspensionsystems, said actuation means comparing said second body movements tosaid second signals and generating comparison signals, said actuationmeans weighting said comparison signals and generating said actuationsignals for adjusting said suspension systems to influence said firstcomponents independently of one another.
 2. The system of claim 1 forcontrolling and regulating a vehicle wherein each suspension systemincludes at least one of a deflectable spring system and a dampingsystem, said control means including means for adjusting said suspensionsystems in discrete steps.
 3. The system of claim 1 for controlling andregulating a vehicle which includes steering angle sensors, wheel speedsensors, acceleration sensors, and a pedal, said system furthercomprising means for determining the state of travel of said vehicle,said state of travel determining means including at least one of:meansfor determining transverse movements of the said vehicle body fromsignals generated by the said steering angle sensors; means fordetermining longitudinal movements of the said vehicle body from signalsgenerated by the said wheel speed sensors; means for determininglongitudinal and transverse movements of the said vehicle body fromsignals generated by the said acceleration sensors; and means fordetermining longitudinal movements of the vehicle by the position of thesaid pedal.
 4. The system of claim 1 for controlling and regulating avehicle which includes a plurality of acceleration sensors disposed atsaid preselected points, wherein said first signal determining meansintegrates signals generated by the said acceleration sensors, saidfirst signals representing vertical accelerations of said preselectedpoints of the said vehicle body.
 5. The system of claim 1 wherein saidsecond signal generating means determines said second signals with atleast one of:sensor means for measuring spring deflection velocities ofthe said suspension systems; and differential means including means formeasuring spring deflections of the said suspension systems and meansfor differentiating said measured spring deflections to calculate springdeflection velocities of the said suspension systems.
 6. The system ofclaim 1 for controlling and regulating a four wheel, two axle vehiclehaving a plurality of adjustable suspension systems, each suspensionsystem capable of exerting a hard damping force and a soft dampingforce, wherein said actuating signal generating means includes means forproviding linkage of signals including signals from said third signalsand weighted signals based on said third signals, said linkage providingmeans calculating linkage signals which represent weighted vertical bodyvelocities at said respective attachment points, and said linkageproviding means calculating said linkage signals according to thematrix: ##EQU11## where a1 is the distance between the center of gravityof the vehicle body and said attachments points of the suspensionsystems above a front axle,a2 is the distance between the center ofgravity of the vehicle body and said attachments points of the wheelsuspension system above a rear axle, 2*b1 is the distance of saidattachment points to the vehicle body above the front axle, and 2*b2 isthe distance of said attachment points to the vehicle body above therear axle, and said second body movement signal determining meansdetermining signals which represent spring deflection velocities of thesaid suspension systems; said system further comprising means foranalyzing said second body movement signals on the basis of theirmagnitude and means for adjusting respective said suspension systemsdepending on the magnitude of said linkage signals, said adjusting meansadjusting a respective one of said suspension systems to a harderdamping force if the direction of the corresponding second body movementsignal is the same as the direction of the relative spring deflectionvelocity, and said adjusting means adjusting a respective one of saidsuspension systems to a softer damping force if the direction of thecorresponding second body movement and the direction of the pertainingspring deflection velocity are opposite.
 7. The system of claim 1wherein said first signals represent the vertical velocities of thevehicle body at four preselected points of the vehicle body, saidchassis control system further comprising means for determining an errorcondition in said chassis control system, said error determining meansgenerating a signal r determined by the equation: ##EQU12## where saidfirst signals are represented by Vk, with k ranging from 1 to 4, withthe elements rik given by the matrix R: ##EQU13## and yi being thecoordinate of said selected point, of index i, in a transverse directionof the vehicle body with respect to a vehicle body-fixed two-dimensionalcoordinate system having a center of gravity of the vehicle body as zeropoint, where the index i=1,2,3,4, and the signal r is compared topredetermined thresholds and an error signal is displayed if saidthresholds are exceeded.